Caroline,
Try this to make clearer.
Suppose depression that you describe is like living in darkness. Now there is some light , but it is dim. You can see to some degree and you try to make your way through the darkness throughout your day. It is difficult to do things in the dark. evrything is hard to focus on, things look veiled, covered, can't make them out.
Now let us suppose that there becomes a beacon of light to shine in your life. Your life is lit up. You can easily do things. You see things that were once veiled or covered that you did not know were there. The darkness is dispelled by the light.
This is just one analogy from my perspective as to overcomming depression. We can curse the darkness, or light a candle.
Lou